So I’m pretty new to this, but have run into a few issues already getting accurate Z from my checkpoints. We did a 160ha scan where gcp’s couldn’t be placed except on the first third of the Eastside. Knowing this would introduce errors I just laid out targets on the East for checkpoints. The GPS was processed in PPK mode, but now I need to apply the orthometric heights from ellipsoid to the images. Not too bad except my pos files aren’t in csv, but that’s for another topic. Once these images are in orthometric height, what do you select for a vertical coordinate system? Images, checkpoints and output should all be arbitrary?